Nearly-logarithmic decay of correlations in glass-forming liquids

TL;DR

This paper explains nearly-logarithmic decay of correlations in supercooled liquids using mode-coupling theory, supported by a schematic model that matches experimental data for specific glass-forming liquids over a wide time range.

Contribution

It introduces a schematic model within mode-coupling theory that captures the nearly-logarithmic decay and the $eta$-peak phenomenon in glass-forming liquids.

Findings

Model reproduces experimental response functions for benzophenone and Salol.

Describes decay behavior from picoseconds to hundreds of nanoseconds.

Supports the $eta$-peak as a manifestation of nearly-logarithmic decay.

Abstract

Nearly-logarithmic decay of correlations, which was observed for several supercooled liquids in optical-Kerr-effect experiments [G. Hinze et al. Phys. Rev. Lett. 84, 2437(2000), H. Cang et al. Phys. Rev. Lett. 90, 197401 (2003)], is explained within the mode-coupling theory for ideal glass transitions as manifestation of the $\beta$-peak phenomenon. A schematic model, which describes the dynamics by only two correlators, one referring to density fluctuations and the other to the reorientational fluctuations of the molecules, yields for strong rotation-translation coupling response functions in agreement with those measured for benzophenone and Salol for the time interval extending from 2 picoseconds to about 20 and 200 nanoseconds, respectively.